Electrically-operated fluid heater



Sept. 3, 1 2 F. WUTHRICH ELECTRICALLY OPERATED FLUID HEATER Filed May 16, 1927 wuwwCo-z WWW ' Yo La WNJ Patented Sept. 3, 1929.

UNITED STATES 1,726,789 PATENT OFFICE.

IBEDEBIC WUTHRICH, OF AARAU, SWITZERLAND, ASSIGNOR TO A.G. KUMMLER & MATTER, OF AARAU, SWITZERLAND, A FIRM.

ELECTRICALLY-OPERATED FLUID HEATER.

Application filed May 18, 1927, Serial No.

This invention relates in general to water or like heaters or boilers, and has more particular relation to such heaters or boilers wherein water is electrically heated and wherein the hot water or like fluid container is enclosed within and maintained in spaced relation with and effectively heat-insulated from an outer surrounding casing or enclosure of reater volume.

It has een difficult heretofore to maintain the heat losses attendant upon the operation of prior fluid heaters of this general type at a sufficiently low value to permit or insure economical operation of the heater. One very considerable source of heat losses has been the means utilized for supporting the inner hot fluid container in position within and securing the same to the outer surrounding casing, this means being ordinarily in the form of metal flanges, straps, or the like, and, likewise, the means for supporting the outlet or discharge pipe for hot fluid and passing the same through the outer casing or enclosure. The wasteful dissipation or losses of heat in these and like ways have greatly reduced the efficiency of these heaters or boilers.

The present invention seeks to avoid losses and reduced efficiency arising from several features of these prior art designs; and, in accordance with the present invention, devices are provided for so supporting the inner or hot fluid container in operative position as to afford efficient support for this inner receptacle and, at the same time, offer the least path for wasteful dissipation or losses of heat; and the invention includes, among its additional features, such arrangements for mounting and securing the hot fluid discharge pipe in operative position as affords minimum chance for losses of heat and consequent reduction in efficiency of the heater. The invention, likewise, includes certain features of design and construction of the inner and outer containers or receptacles which facilitate the positioning or centering and the supporting of the inner receptacle in operative position within the outer receptacle, and the efficient discharge of hot Water from the inner receptacle to the hot water outlet or discharge pipe.

It is an object of the present invention to provide an improved design and construction of fluid heater which affords or insures minimum wasteful loss or dissipation of heat from the hot fluid container.

It is a further object of the present inven- 191,768, and in Switzerland July 6, 1926.

tion to provide an improved design and construction of fluid heater of the type embodymg an outer casing and an inner hot fluid container spaced from the outer casing, wherein the means for supporting and maintaining the inner casing or container in operative position involves the use of a minimum of heat-conductive material in contact with such casing or container.

It is a further object of the present invention to provide an improved design and construction of. fluid heater of the above dcfined character, wherein the disposition of the hot fluid discharge-pipe and the method of leading off and connecting the latter to the inner receptacle insures a minimum loss or waste of heat and also insures efficient and satisfactory control of the discharge from the inner receptacle.

It is a further object of the present invention to provide an improved design and construction of fluid heater of the above defined character and embodying characteristic features of the inner and outer receptacles which facilitate the positioning of the inner receptacle and the supporting thereof in operative position, and, ing in the inner receptacle of the desired heating elements and controlling devices therefor, these features affording a maximum of simplicity in design and construction and a minimum of expense in manufacture.

These and other objects and advantages are attained by the present invention, various novel features of which will be apparent from the accompanying description and drawings, illustrating an embodiment of the invention and will be more particularly pointed out in the claims.

In the accompanying drawings:

Fig. 1 is a view in vertical section of an electrically operated fluid heater embodying features of the present invention.

Fig. 2 is a sectional view in the plane of the line IIII of Fig. 1.

In accordance with the disclosure of the drawings wherein the invention is shown as embodied in a hot water heater of the type which is capable of heating water or like fluid to a predetermined temperature and maintaining a body of such water at such desired temperature and available for use at any time, a cylindrical inner casing or drum 10, ordinarily pressed or formed from sheet metal, is disposed within and spaced from an outer likewise, facilitate the mounterably-turned downward to provide a flange or lip 15. A cylindrical ring or annular element 16, preferably of mechanically strong heat-insulating material, as wood or the like, or of metalinsulated at its upper end, is rigidly secured within the aperture in the lower cap 14, being preferably riveted or bolted to the lip 01' flange 15, this cylindrical element lfi'extending upwardly to a conside'rable extent, centrally of the outer casing 12.

" The inner casing or receptacle 10 is supported in operative position by resting upon the upper end of the cylindrical element 16; and this inner receptacle is centrally positioned within the outer casing 12 by means ,of a lip or downward extension 18 formed in the material surrounding a central aperture 'in the lower end of the inner receptacle 10,

this downwardly extending lip being provided with an outwardly extending flange 19 at its lower end, and this flange '19 may be of such shape and size as to fit with a fairly close sliding or guiding fit within and along the upper portion of the inner surface of the cylindrical element 16, serving to guide the inner casing 10 to and maintain it in central position within the outer casing.

The upper end of the inner casing 10 may be held in desired central and spaced relation with respect to the outer casing 12 by means of a series of segmental blocks or pieces 21, of heat-insulating material, which may be separately formed, or may be secured to each other by ribs, and may be attached to either the inner or outer casing for the purpose of being maintained in operative position. With the inner casing placed in operative position relative to the outer casing, as indi-.

cated in the drawing, the space between the two casings may be filled with suitable granulated or equivalent heat-insulating material, and the upper cover plate or closure 13 attached in operative position, as indicated.

A closure plate 25 is detachably secured to the flange 19 at the lower end of the inner receptacle 10, in any suitable fluid-tight manner. This closure plate 25 is preferably so formed as to provide suitable means for mounting in operative position a heating element, indicated at 26, and a thermostatic or other controlling device, indicated at 27, for regulating the temperature of the fluid within the inner casing. It will be apparent that on removal of the closure 25 and the parts attached thereto, the inner casing may readily be cleaned.

A cold water inlet pipe 31, provided with a suitable controlling valve, passes through the outer and inner casings 12 and 10, respectively, emerging into the latter and suitably deflected at a point adjacent the lower end thereof. A discharge pipe for hot fluid, indicated at 32, passes from the upper end of the inner casing 10, through the entire length thereof and, emerging therefrom, passes through the outer casing 12 to a suitable discharge point.

The upper end of the inner receptacle 10 is preferably formed with an integral nipple, indicated at 34, the upper end of the discharge pipe 32 projecting upwardly through the upper end of the nipple and being secured therein in a fluid-tight manner, as by welding, soldering, threading, or the like. Openings 35 in the discharge pipe 32 permit the discharge or passage of hot fluid from the inner container 32 to the discharge pipe. The preferred arrangement for securing the outlet pipe 32 in operative position includes such formation of the nipple 34 at the upper end of the inner casing as presents a dome or bonnetshaped space 36 above the lower end of the discharge openings 35 in the outlet pipe. Through this arrangement, the upper level of the fluid in the container 10 is at a point of substantially reduced cross-sectional area, and the space above this level is of relatively small volume. Through this latter feature of construction, the space above the water level in the inner casing within which water or other vapors or gases may form and be placed under pressure, is considerably reduced, a feature which has a desirable effect in avoiding or minimizing drip or uncontrolled discharge to the outlet pipe 32 at the end of the siphoning or drawing-off operation after of the inner casing 10, a feature of eonstruction which will permit the attachment to the upper end of this discharge pipe of a substitute or supplemental discharge which may be passed through the upper end closure 13 of the outer receptacle 12. However, in the preferred design and method of operation, the discharge is through the lower end of the discharge pipe 32, and the upper end of the disehar e pipe is closed by a screw cap 37, or the like, which permits access to the interior of the pipe 32, as for cleaning purposes. And with the discharge pipe 32 passing through the middle or body of the inner casing 10, there results a minimum waste or -o the cylindrical element 16. The

extendin e lower en space between this lower closure 41 and the removable closure plate 25 may be filled with any desired form of heat-insulating material. Likewise, the closure 41 is preferably suitably apertured, as indicated, for the reception and passage therethrough of. leads which serve to connect the heating element 26 and its regulator 27 in operative relation with respect to a sup 1y circuit.

It will be apparent that in-accordance with the present invention an arrangement is provided which insures simplicity of design and construction of the several parts of the fluid heater and their assembly in operative position, and, likewise, insures extremely ellicient operation.

It should be understood that the invention claimed is not limited to the exact details of construction shown and described hereinabove, for it is intended to cover obvious modifications which will occur to persons skilled in the art.

It is claimed and desired to ters Patent:

1. In an electrically operated fluid heater, an outer shell, a fluid-containing shell within and spaced from said outer shell, and means for supporting said inner shell within and maintaining the same in spaced relation to said outer shell, said means comprising an annularly formed element secured adjacent one end thereof to the lower side of one of said shells and having edgewise bearing and supporting engagement at its other end with the lower side of said other shell.

2. In an electrically operated fluid heater, an outer shell, a fluid-containing shell within and spaced from said outer shell, and means carried by said outer shell for supporting said inner shell within and maintaining the same in spaced relation to said outer shell, said means comprising an annular element secured at one end thereof to the lower side of one of said shells and having bearing engagement at its other end with the lower side of said other shell, and the portion of said annular element adjacent at least one of said shells being of heat-insulating material.

3. In an electrically operated fluid heater, an ou er shell, an inner fluid-containing shell spaced from said outer shell, said inner and position about the downwardly i 15 on the outer casing 12 or t secure by Letouter shells being provided with alined apertures, and means for supporting said inner shell within and maintaining the same in spaced relation to said outer shell, said means including an upwardly extending tubular element of heat-insulating material carried by said outer shell and bearing at its upper edge against the lower side of and supporting said inner shell in operative position.

4. In an electrically 0 erated fluid heater, an outer shell, an inner -uid-containing shell spaced from said outer shell, said inner and outer shells being provided with alined apertures at their lower ends, and said inner shell having at its lower side a reduced centrally disposed neck provided with a removable closure at its lower end, and means for supporting said inner shell within and maintaining the same in spaced relation to said outer shell,

said means including an element of tubular form carried by said outer shell and having a portion extending upwardly outside of the reduced neck of said inner shell and engaging with and supportin said inner shell.

5. In an electricafiy operated fluid heater, an outer shell, an inner fluid-containing shell spaced from said outer shell, said inner and outer shells being provided with alined apertures at their lower ends, a removable closure for the aperture in the lower end of said inner shell, an electrical heating element carried by and removable with said closure, and means for supporting said inner shell within and maintaining the same in spaced relation to said outer shell, said means being carried by one of said shells and bearing against but unattached to the lower end of the other shell and being substantially ineffective to conductheat from said inner shell.

6. In an electrically operated fluid heater, an outer shell, an inner fluid-containing shell Within and spaced from said outer shell, said inner and outer shells being provided with alined apertures at their lower side, a M51110"- able closure for the aperture at the'lower end of said inner shell, an electrical heating element and a controlling device therefor carried by and removable with said closure, and means for supporting said inner shell within and maintaining the same in spaced relation to said outer shell, said means including-an upwardly extending tubular element carried by said outer shell and bearing upon the lower side of said inner shell at points laterally outside of the aperture therein.

7. In an electrically operated fluid heater, an outer shell, a fluid-containing shell within and spaced from said outer shell and having a convex lower end face, and an annularly arranged supporting and centering device for said inner shell carried by the lower end of said outer shell and bearing against the convex lower face of said inner shell and maintaining said inner shell in spaced relation as tosaid outer shell.

8. In an electrically operated fluid heater, an outer shell, a fluid-containing shell within and spaced from said outer shell and having a tubular extension of reduced cross-sectional I duct heat from said inner shellto said outer duced cross-sectional area, an inlet pipe eom-' municating with said inner shell, and an outlet pipe for heated fluid having the inlet thereto disposed at the upper end of said inner shell.

10. In an electrically operated fluid heater, an outer shell, a fluid-containing shell within and spaced from said outer shell, said inner shell being formed at its upper end with a portion of reduced cross-sectional area, an inlet pipe communicating with said inner shell, and a hot fluid outlet pipe disposed within said inner shell and having the inlet thereto located in the portion of reduced cross-sectional area at the upper end of said inner shell.

11. In an electrically operated fluid heater, an outer shell, a fluid-containing shell within and spaced from said outer shell, said. inner shell being formed at its upper end with a portion of reduced cross-sectional area, an inlet pipe communicatingwith said inner shell, and a hot fluid outlet pipe disposed within said inner shell and having the inlet thereto located in the portion of reduced cross-sectional area at the upper end of said inner shell, and passing downwardly through the body of said inner shell.

12. In an electrically operated fluid heater, an outer shell, a fluid-containing shell within and spaced from said outer shell, said inner shell being formed at its upper end with a portion of reduced cross-sectional area, an inlet pipe communicating with said inner shell, and a hot fluid outlet pipe disposed within said inner shell and having the inlet thereto disposed in the reduced portion at the upper end of said inner shell at a point which leaves a substantial air or vapor space of reduced cross-sectional area above the inlet to said discharge pipe.

13. In an electrically operated fluid heater, an outer shell, a fluid-containing shell within and spaced from said outer shell, an inlet pipe communicating with said inner shell, and an outlet pipe for heated fluid passing downwardly through said inner shell and having the inlet thereto disposed adjacent the upper end of said inner shell, the upper end of said outlet pipe being secured in the material of the upper end of said inner shell.

14. In an electrically operated fluid heater, an outer shell, an inner fluid-containing shell spaced from said outer shell and having a portion of reduced cross-sectional area at its upper end, an inlet pipe communicating with said inner shell, and a discharge pipe for h ated fluid passing downwardly through said inner shell and having the inlet thereto located in said portion of reduced cross-sectional area, the upper end of said discharge pipe passing through and being secured in the material of said portion of reduced crosssectional areaat the upper end of said inner shell, and a removable closure for the upper end of said discharge pipe.

15. In an electrically operated fluid heater, an outer shell, a fluid-containing shell within and supported in spaced relation from said outer shell, said inner and outer shells being provided with alined apertures at their lower ends, a centering flange formed on said inner shell about the aperture therein and having a laterally extending portion having a guiding fit with a cooperative portion of said outer shell, and a removable closure for the lower end of said flange. 1

16. In an electrically operated fluid heater, an outer shell, an inner fluid-containing shell supported in spaced relation from said outer shell, said inner and outer shells being provided with alined apertures at their lower ends, a substantially cylindrical element carried by said outer shell, a centerin projection formed on said inner shell 21 out the opening therein and having a guiding portion cooperative with said cylindrical element, and a removable closure for the lower end of said inner shell.

17. In an electrically operated fluid heater, an outer shell, an inner fluid-containing shell supported in spaced relation from said outer shell, the upper end of said inner shell being formed with a substantially central and integral dome-shaped portion of reduced crosssectional area, said inner and outer shells being provided with alined apertures at their lower ends, a substantially cylindrical element carried by and projecting from the lower end of said outer shell, an integral centering flange formed on said inner shell about the aperture therein and having a laterally extending portion having a guiding fit with said cylindrical portion, and a removable closure for the lower end of said flanged extension.

18. In an electrically operated fluid heater, an outer shell, a fluid-containing shell within and spaced from said outer shell and having a reduced neck at its lower side, an annularly arranged supporting and centering device for said inner shell carried by the lower end of said outer shell and bearing against the lower side of said inner shell, a closure for the lower end of said inner shell, and an electrical heating element carried by said closure and disposed within said inner shell.

In witness whereof I aflix my signature 

